> So, I'm looking at options to build/hack a
> GPS device, combined with some sort of
> embedded gentoo friendly Tablet.
>
>
> I'm thinking of multiple channels
> of audio output so it is a 5.1 mp3 player too,
> for a boat or a RV or an car. Mobile so it can
> be moved between vehicles with a quick connect
> to sensors and speakers.

Nokia N900 or new N9 (I have an N9, but the N900 probably has more
hackers around it and cheaper second hand items)
Build something around a gumstix - not that cheap, but I think they have
all the bits ready to plug together. Probably low enough power you could
battery power it
Very easy to hack is a PC Engines Alix + laptop screen. (In some ways
that's called a 1 laptop per child I guess.... Add that to the list)
Good luck finding a Gentoo friendly tablet? I would be interested if
you find something?
Good luck
Ed W